Control mechanism for furnace blowers



3! 1935.. R. G. STANDERWICK 2,U7,7W

CONTROL MECHANISM FOR FURNACE BLOWERS Filed Feb. 17, 1933 I %N 5 i. \N

Id G. Stanciervvic; k,

H s Attlorneg Inventor:

e ina i U Patented July 9, 1935 mm as '7 conrnonmnousmsivrlroa FURNACE,BLOWER'S Reginald G; Standerwiek, Marblehead, esa, assignor to GeneralElectric Company, a corporation of New York Application February 17,

1933; Serial No. 657,250

The'present invention relatesto furnaces such ,as Bessemer converters,and like consumers of air or gas wherein air for blowing the furnaces issupplied by a turbine driven centrifugal eempressor, and especially tocontrol means for such rappara'tusr The control of such apparatus ofierspeculiar difficulties in that the furnace'or furnaces are locatedusually a considerable distance from the turbo-compressor, requiringalong'pipe 'duringi'the operation of the furnace, the com- ;pressoi mustbe shut down, and started up again frequently. 1 V

' The object of my invention is to provide an "or thistype, and foraconsideration ofivvhatl believe to benovel and my invention',,attentionis directed to the following specification and'the claims appendedthereto;

In the drawing, the figure is a diagrammatic view of an installationembodyingfmy invention, it being in the drawing shown'appli'ed to jtwoBessemer converters receiving air from the same turbo-compressor set. i"Referring to V the drawing; the Bessemer converters I and'2areconnected by conduits 3 and "4Qto a discharge conduit 5 ofoentr'ifugal'c'om- 'pressor or blower 6 drivenby aneIastic' fluidturbine or prime mover 'I." In conduit 5, is a non-return valve 511which serves to prevent back 'blow in conduit 5 toward the compressor;The converters l and 2 are indicated as beingf'located a considerabledistance from the turbo compres- 501 set (this being the'condition metwith usuf ally) which means that the pipe line comprising conduits 3,4and 5 is relatively long and has a large volumetric capacity.The'turbinefT is provided with valve means 8 for controlling the vsupply of elastic fluid to the turbine and with "a speed governor 9driven from the turbine'shaft.

' it'being connected toa condenser I IJThe compressor is provided withan intake conduit l2 7 Connected to an end portion of the'discharge 5conduit 5, that is in the vicinity of the compressor,

is a waste conduit or dumping pipe I3, in which is located a blow-ofi,dumping or wastevalve l4. Conduit 'l3 may discharge directlytoatmosphere or, as shown, it may be connected to'the com- ;50' 'pressorinlet conduit l2. Valve M has its stein connected'to 'a piston of ahydraulic motor, the cylinder of which'is indicated atlG. Admission ofactuating fluid to cylinder l6 is controlled by a pilot valve I1, I8being the supply condu t 65' to the pilot valve and IS the dischargeconduit linetof relatively large capacity, and vin that ea governorlever241 One end of lever 24 is pivotally connected to a lever 25 and theother i direction to move valve means 8 to closed posif therefroml Thestem of pilot valve I! is con- 7 nected to avplunger 200i anelectro-magn'et, the

winding of; which is indicated at 2|. Pilot valve 7 l1 hasonly twopositions. 'When winding 2! is deg'energized, pilot valve l1 occupies aposition to 5 "admitactuating fluid to the outer end of the cylinderl6,'thereby holding valve l4 closed, and 'when winding 2| is energized,the position of the ,pilotivalveis reversed, admitting actuating fluidto the inner end of cylinder [6 to force valve [4 10 7 to open positionand hold it there. In other words, when winding 2| is deenergized, valveI4 is held closed and when winding 2| is energized, valve l4. is heldopen. improved control mechanism for an installation Inconduits 3 and 4are manually controlled :15

.' valves 2tl'fandl23 bymeans of which the operator varies the quantityof air required during operation of the converters. 1

v Speedgovernor '9 has a spindle connected to end is connected" to theplunger 26 of an electromagnet, the winding of which is indicated at 21.

T Winding 2!v is normallydeenergized and when deenergized, a spring 28holds the right hand end .25 of governor lever 24 against a fixed stop29; One

n end of lever is connected to valve means 8 and the arrangement is suchthat when winding 21 is energized, it turns governor lever 24 in a v 30tion, lever 24 pivoting on the spindle of governor 9. .It is desirablethat this movement be retarded somewhat so that in operation valve Mwill be opened wide before valve means 8 is closed, In the presentinstance this is effected by Pa suitabledash pot 2'l which serves toretard upward movement of plunger 26.

It is desirable in an installation of this type [that evenwhen valvemeans 8 is closed, sufiicient Qe'lastic fluid flows by it to keep theturbine turning 40 The exhaust for the turbine is indicated at in,

over at a low speed. For this purpose, the valve lm'eans is providedwith a small opening 39 through it, although any other suitablearrangement'rnay be used for this purpose.

" Electromagnet winding 2| and electromagnet ffi winding 21 areconnected in multiple to a remote controlrhechanism comprising a switch3!, one

terminal of which is connected to a suitable source of electrical supplyindicated at 32. With is released, its right hand end being held inengagement with the stop 29. When switch 3| is 'clcsed, the windings ofboth electromagnets are 5 indicating the pressure therein.

energized, the energization of winding 2| serving to open valve l4 andthe energization of winding 21 serving to close valve 8.

The left hand end of lever 25 is connected to a pressure responsivedevice 33 which in turn is connected by a pipe 34 to discharge conduit5. In the present instance, the pressure responsive device which forms apart of the turbine governing mechanism is shown as comprising a casing35 in which is located a corrugated bellows .36 having its stem 31pivotally connected to lever 25. Pipe 34 connects to the lower end ofcasing 35. Surrounding stem 31, between the top of casing 35 and anadjustable spring plug 38 on stem 31, is an adjusting spring 39. .Spring39 is a tension spring operating in a direction opposed to the pressurein casing 35. Spring plug 38 is threaded on stem 31 and may be adjustedby turning'it manually or by means of an electric motor 40 which isconnected to .a gear 4|, which forms a part of spring plug 38, bymeans'of a bevel gear 42 and a spur gear 43. When motor 40 is operatedin one direction or the other, it turns nut 4| to either increase ordecrease the tension of the spring 39. The nut and spring plug travelalong the threaded rod 31. The two windings of reversing motor 40 areconnected to a switch 44. By means of switch 44, the pressure responsivedevice 33 may be adjusted or set for the desired pressure. p

The control switches 3| and 44 and the control 'means for valves 22 and23 are located adjacent to the converters and to each other so that theoperator at the Bessemer converters can manipulate them conveniently.Adjacent the operator is a pressure gage 45 connected to conduit 5 forThe operation is as follows: When the molten stock is being poured intothe converters to load the same, switch" 3| is closed, therebyenergizing windings 2| and 21. This serves to open wide the blow-off orwaste valve l4 and to close entirely valve means 8.

Closing valve means 8 shuts ofl the supply of elastic fluid to theturbine except for the amount which leaks through opening 30, this beingsuflicient to keep the turbine turning over at a relatively low speed.As soon as the converter is loaded, the operator opens switch 3|whereupon waste valve I4 is promptly closed and valve means 8 is thrownwide open. The turbine quickly comes up to maximum speed, this being thespeed for which the governor 9 is set. Ordinarily,

the speed governor is set for a speed somewhat' ing valve means 8 toobtain the desired pressure in discharge conduit 5. In this connection,it will be seen that when the pressure in conduit 5 increases, thepressure responsive device closes valve means 8 somewhat to bring thepressure back to normal value and when the pressurein conduit 5decreases below normal value, pressure responsive device. 33 serves toopen valve means 8 to increase the speed and bring the pressure back tonormal value. After the compressor pressure reaches normal value, theoperator then .closing of the non-return valve.

manipulates valves 22 and 23 to supply the desired amount of air to theconverters. After the blowing operation is completed, the operatorcloses the switch 3|, thus again bringing the turbine quickly to idlingcondition with the blow- 5 off valve I4 open and the valve means 8closed. The cycle of operation canbe, then repeated.

The provision of dash pot 2! retards somewhat the closing movement ofvalve means 8 so that valve l4 will be opened wide prior to the 10closing of valve means 8. As soon as valve |4 opens, the pressure inconduit 5 in advance of non-return valve 5 drops, thus effecting a quickBy this arrangement, it is assured that there is a flow of 15 airthrough waste conduit 3 suflicient to pre vent pulsationbefore theclosure of valve means 8 has caused the compressor to drop in speed.

The waste valve |4 serves to prevent pulsation of the compressor attimes when the operator in 20 shutting down might close valves 22 and 23before the turbine has appreciably dropped in speed.

By means of switch 44, pressure responsive device 33 can be adjusted tovary the pressurein-25 conduit 5 or it can be used to slowly shut downthe turbine.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. The combination with a gas compressor, "30 of a long conduitconnected to the discharge of the compressor, the free conduit endportionincluding a valve for controlling the flow of gas, and means fordumping gas from the conduit for rapidlyinterrupting the flow of gas inthe conduit to prevent pulsation of the compressor, said meanscomprising a pipe connected to'the conduit end portion adjacent thecompressor, a dumping valve in the pipe andmeans for oper- I ating thedumping valve including an actuating 40 member located in proximity ofthe free conduit end portion. p 2. The combination with a gascompressor, of

a long conduit connected to the discharge of the ing a valve forcontrolling the flow of gas, and

means for dumping gas from the conduit for rapidly interrupting the flowof gas in the conduit .to prevent pulsation of the compressor, saidmeans comprising a'pipe connected to the con- 50 duit end portionadjacent the compressor, a dumping valve in the, pipe, means foroperating the dumping valve including an actuating member located inproximity of the free conduit endportion, and a non-retum valve in theconduit' behind its connection with said pipeas regards the direction offlow therein to minimize the pulsation of gas during the dumpingoperation.

3. The combination with a turbo-compressor of a. long conduit connectedto the discharge of 60 tion, means for rapidly interrupting the flow ofgas in'the conduit comprising a pipe connected to the conduit endportion adjacent the com-, pressor and a valve in the pipe for dumpinggas I from the conduit,.and remote control means including a memberadjacent the free conduit end portion for actuating the governingmechanism to efiect complete closing of the turbine valve.

4. The combination with a blower having a" discharge conduit ofconsiderable length, of a control valve in the free end of the conduitfor controlling the discharge of air from the conduit, a dumping conduitwith a valve connected to the conduit adjacent the blower for dumpingair from the conduit, and means including an actuating member adjacentthe discharge end of the conduit for operating the dumping valve toprevent pulsation of the blower when the control valve is closed.

5. The combination with a blower having a discharge conduit ofconsiderable length, of a control valve in the free end of the conduitfor controlling the discharge of air from the conduit,

a dumping conduit with a valve connected to the conduit adjacent theblower for dumping air from the conduit, means including an actuatingmember adjacent the discharge end of the conduit for operating thedumping valve to prevent pulsation of the blower when the control valveis closed, and a non-return valve in the conduit behind the dumpingconduit as regards the flow in the conduit tovprevent back flow in theconduit during dumping operation.

6. In a turbo-compressor, the combination of a compressor, a turbine fordriving the compressor having an inlet valve with an opening in thevalve member for by-passing elastic fluid to cause idle running of theturbo-compressor when said valve is shut, and a governing mechanism fornormally operating the valve comprising a pressure governor connected tothe compressor discharge conduit and remote control means for closingthe valve.

REGINALD G. STAN DERWICK.

